A Break From The Alex Smith Drama: Urbanization Is Supersizing Spiders

City living brings with it a few shifts in lifestyle compared to rural habitation: shorter commutes, accessible shops and, often, an over-reliance on restaurant dining and fast food. Another side effect of the congested, cramped, cement-laded city life is that the temperature tends to be a little warmer year-round, a shift known as the “urban heat island” effect.

As it turns out, these changes aren’t only affecting cities’ human populations. In Australia, where spiders already have a propensity to be terrifyingly large, new research by University of Sydney PhD candidate Lizzy Lowe, says The Age, found that Sydney’s higher temperatures and easier access to food are driving the spiders to grow even bigger.

She studied the golden orb weaver in three types of environments in and around Sydney – urban parks, remnant bushland and continuous bushland. Twenty sites were studied and, for each spider web found, she assessed its proximity to man-made objects and vegetation.

Comparing the sizes of the spiders, she found that the city spiders outpaced the country spiders. And, though her research focused only on Golden orb weaver spiders, she suggests that the same effect can probably be seen in other species.

Both vertebrates and invertebrates follow a general rule, known as Haller’s Rule, when it comes to brain and body size: “The brains of smaller animals are larger relative to body size than large-bodied forms.” Human brains are about 2 to 3 percent of our body mass, while the brains of some ants are 15 percent of their body mass. But the difference is even bigger when we talk spiders, according to a new study in Arthropod Structure & Development.

A group of researchers from the Smithsonian Tropical Research Institute and the University of Costa Rica measured (with great difficulty, I’m sure) the mass of the brains in adults of nine species of web-weaving spiders and in the young spiderlings of six of those species. The adults ranged in size from a tenth of a milligram to 2,000 milligrams (about .07 ounces).

“We discovered that the central nervous systems of the smallest spiders fill up almost 80 percent of their total body cavity, including about 25 percent of their legs,” says William Wcislo, a staff scientist at STRI in Panama. “The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors.”

It seems that there are limits on how small a brain can be and still function properly. Brain cells cannot be smaller than the nucleus that contains all of the spider’s genes. Nerve fibers cannot get too thin or they wouldn’t be able to adequately carry and transfer a nerve signal.

As a result, the young spiderlings of the smallest spider species have bulging bodies to make room for all the necessary brain cells.

Both vertebrates and invertebrates follow a general rule, known as Haller’s Rule, when it comes to brain and body size: “The brains of smaller animals are larger relative to body size than large-bodied forms.” Human brains are about 2 to 3 percent of our body mass, while the brains of some ants are 15 percent of their body mass. But the difference is even bigger when we talk spiders, according to a new study in Arthropod Structure & Development.

A group of researchers from the Smithsonian Tropical Research Institute and the University of Costa Rica measured (with great difficulty, I’m sure) the mass of the brains in adults of nine species of web-weaving spiders and in the young spiderlings of six of those species. The adults ranged in size from a tenth of a milligram to 2,000 milligrams (about .07 ounces).

“We discovered that the central nervous systems of the smallest spiders fill up almost 80 percent of their total body cavity, including about 25 percent of their legs,” says William Wcislo, a staff scientist at STRI in Panama. “The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors.”

It seems that there are limits on how small a brain can be and still function properly. Brain cells cannot be smaller than the nucleus that contains all of the spider’s genes. Nerve fibers cannot get too thin or they wouldn’t be able to adequately carry and transfer a nerve signal.

As a result, the young spiderlings of the smallest spider species have bulging bodies to make room for all the necessary brain cells.

Lynx spider (family Oxyopidae), any of several groups of active spiders (order Araneida) that do not build a nest or web but capture their prey by pouncing upon them. Lynx spiders are distributed worldwide and in North America are most common in southern regions. The eyes are arranged in a hexagon, and the abdomen usually tapers to a point. Lynx spiders are usually found on vegetation, seeking insect prey.

I just found a black widow (shut up; the spider) walking across the lobby at Walmart last week. She did not kill me, and I did not kill her. Picked her up with a piece of paper and she hung off it on a web (that's how I saw the hourglass) and I let her outside. Hopefully to munch on a Trick-or-Treater later...

I just found a black widow (shut up; the spider) walking across the lobby at Walmart last week. She did not kill me, and I did not kill her. Picked her up with a piece of paper and she hung off it on a web (that's how I saw the hourglass) and I let her outside. Hopefully to munch on a Trick-or-Treater later...

Spiders be smart....seeking their prey where it's the fattest and the slowest. Once they get their taste of human flesh god help save the rest of walmart from the zombie spiders!!!

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"Political correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t*rd by the clean end"

Spiders....gotta lovem. I like it when I walk outside on the deck and the little ****ers have built a web from post to post and you walk through the shit.

Spiders.... kill all of them.

This.
There are very few things I completely despise than spiders. They just simply creep the **** out of me. A few months ago I was sitting on my couch watching tv and I felt a very light bump on my head. Yep, ****ing spider, guessing it fell off the ceiling. I jumped straight off the couch, and it wasn't even that big of a spider.
Every time I see a spider in my house now I go into full assassin mode.

The current study tested the association between fear and perception in spider phobic individuals (n = 57) within the context of a treatment outcome study. Participants completed 5 post-treatment Behavioral Approach Tasks (BATs) in which they encountered a live spider and were asked to provide spider size estimates. Consistent with predictions, results indicated that high levels of fear were associated with magnified perception of phobic stimuli. Specifically, we found a significant positive correlation between size estimates and self-reported fear while encountering spiders. Together with previous findings, these results further support the notion that fear is involved in the encoding and processing of perceptual information.

Many of us are not so fond of spiders, with their multiple eyes and creepy-crawly legs. But some of us get it worse. For arachnophobes, spiders aren't just unsettling or gross; they're petrifying. Seeing a spider, or even a picture of a spider, sends arachnophobes' hearts racing and paralyzes their bodies with fear. In 2012, a team of psychologists discovered an unfortunate aspect of arachnophobia: the more scared you are of spiders, the bigger the spider looks to you.

In a study, people who self-described as afraid of spiders were made to repeatedly come in close proximity to a series of tarantulas. They then had to draw down on a sheet how big the spider was, tip to tip, says Marc Abrahams in the Guardian. Using a separate assessment of arachnophobia, the researchers found the relationship between fear and perceived size.